Oct 28, 2022 · Oct 28, 2022 · Oct 28, 2022 · Oct 28, 2022 · Oct 28, 2022 · Oct 28, 2022
diff --git a/Makefile b/Makefile
@@ -196,6 +196,7 @@ PACKRATLIST=
 UTF8_LOCALE=	en_US.utf8
 
 # Non-default libraries needed to link.
+# On some hosts, this should have -lintl unless CFLAGS has -DHAVE_GETTEXT=0.
 LDLIBS=
 
 # Add the following to the end of the "CFLAGS=" line as needed to override
@@ -208,14 +209,18 @@ LDLIBS=
 #	For example, N is 252460800 on AmigaOS.
 #  -DHAVE_DECL_ASCTIME_R=0 if <time.h> does not declare asctime_r
 #  -DHAVE_DECL_ENVIRON if <unistd.h> declares 'environ'
+#  -DHAVE_DECL_TIMEGM=0 if <time.h> does not declare timegm
 #  -DHAVE_DIRECT_H if mkdir needs <direct.h> (MS-Windows)
-#  -DHAVE_GENERIC=0 if _Generic does not work
+#  -DHAVE_GENERIC=0 if _Generic does not work*
-#  -DHAVE_GETRANDOM if getgrandom works (e.g., GNU/Linux)*
+#  -DHAVE_GETRANDOM if getrandom works (e.g., GNU/Linux),
-#  -DHAVE_GETTEXT if 'gettext' works (e.g., GNU/Linux, FreeBSD, Solaris)*
+#	-DHAVE_GETRANDOM=0 to avoid using getrandom
+#  -DHAVE_GETTEXT if gettext works (e.g., GNU/Linux, FreeBSD, Solaris),
+#	where LDLIBS also needs to contain -lintl on some hosts;
+#	-DHAVE_GETTEXT=0 to avoid using gettext
 #  -DHAVE_INCOMPATIBLE_CTIME_R if your system's time.h declares
 #	ctime_r and asctime_r incompatibly with the POSIX standard
 #	(Solaris when _POSIX_PTHREAD_SEMANTICS is not defined).
-#  -DHAVE_INTTYPES_H if you have a non-C99 compiler with <inttypes.h>
+#  -DHAVE_INTTYPES_H=0 if <inttypes.h> does not work*
 #  -DHAVE_LINK=0 if your system lacks a link function
 #  -DHAVE_LOCALTIME_R=0 if your system lacks a localtime_r function
 #  -DHAVE_LOCALTIME_RZ=0 if you do not want zdump to use localtime_rz
@@ -225,15 +230,17 @@ LDLIBS=
 #	functions like 'link' or variables like 'tzname' required by POSIX
 #  -DHAVE_SETENV=0 if your system lacks the setenv function
 #  -DHAVE_SNPRINTF=0 if your system lacks the snprintf function
-#  -DHAVE_STDINT_H if you have a non-C99 compiler with <stdint.h>*
+#  -DHAVE_STDCKDINT_H=0 if neither <stdckdint.h> nor substitutes like
+#	__builtin_add_overflow work*
+#  -DHAVE_STDINT_H=0 if <stdint.h> does not work*
 #  -DHAVE_STRFTIME_L if <time.h> declares locale_t and strftime_l
 #  -DHAVE_STRDUP=0 if your system lacks the strdup function
 #  -DHAVE_STRTOLL=0 if your system lacks the strtoll function
 #  -DHAVE_SYMLINK=0 if your system lacks the symlink function
-#  -DHAVE_SYS_STAT_H=0 if your compiler lacks a <sys/stat.h>*
+#  -DHAVE_SYS_STAT_H=0 if <sys/stat.h> does not work*
 #  -DHAVE_TZSET=0 if your system lacks a tzset function
-#  -DHAVE_UNISTD_H=0 if your compiler lacks a <unistd.h>*
+#  -DHAVE_UNISTD_H=0 if <unistd.h> does not work*
-#  -DHAVE_UTMPX_H=0 if your compiler lacks a <utmpx.h>*
+#  -DHAVE_UTMPX_H=0 if <utmpx.h> does not work*
 #  -Dlocale_t=XXX if your system uses XXX instead of locale_t
 #  -DRESERVE_STD_EXT_IDS if your platform reserves standard identifiers
 #	with external linkage, e.g., applications cannot define 'localtime'.
@@ -280,7 +287,7 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
   -Wdeclaration-after-statement -Wdouble-promotion \
   -Wduplicated-branches -Wduplicated-cond \
   -Wformat=2 -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation \
-  -Winit-self -Wlogical-op \
+  -Wimplicit-fallthrough=5 -Winit-self -Wlogical-op \
   -Wmissing-declarations -Wmissing-prototypes -Wnested-externs \
   -Wnull-dereference \
   -Wold-style-definition -Woverlength-strings -Wpointer-arith \
@@ -293,7 +300,7 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
   -Wtrampolines -Wundef -Wuninitialized -Wunused-macros -Wuse-after-free=3 \
   -Wvariadic-macros -Wvla -Wwrite-strings \
   -Wno-address -Wno-format-nonliteral -Wno-sign-compare \
-  -Wno-type-limits -Wno-unused-parameter
+  -Wno-type-limits
 #
 # If your system has a "GMT offset" field in its "struct tm"s
 # (or if you decide to add such a field in your system's "time.h" file),
@@ -340,14 +347,11 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
 # If you want functions that were inspired by early versions of X3J11's work,
 # add
 #	-DSTD_INSPIRED
-# to the end of the "CFLAGS=" line.  This arranges for the functions
+# to the end of the "CFLAGS=" line.  This arranges for the following
-# "offtime", "timelocal", "timegm", "timeoff",
+# functions to be added to the time conversion library.
-# "posix2time", and "time2posix" to be added to the time conversion library.
 # "offtime" is like "gmtime" except that it accepts a second (long) argument
 # that gives an offset to add to the time_t when converting it.
 # "timelocal" is equivalent to "mktime".
-# "timegm" is like "timelocal" except that it turns a struct tm into
-# a time_t using UT (rather than local time as "timelocal" does).
 # "timeoff" is like "timegm" except that it accepts a second (long) argument
 # that gives an offset to use when converting to a time_t.
 # "posix2time" and "time2posix" are described in an included manual page.
@@ -495,6 +499,11 @@ TARFLAGS=	`if tar $(GNUTARFLAGS) --version >/dev/null 2>&1; \
 # Flags to give 'gzip' when making a distribution.
 GZIPFLAGS=	-9n
 
+# When comparing .tzs files, use GNU diff's -F'^TZ=' option if supported.
+# This makes it easier to see which Zone has been affected.
+DIFF_TZS=	 diff -u$$(! diff -u -F'^TZ=' - - <>/dev/null >&0 2>&1 \
+			   || echo ' -F^TZ=')
+
 ###############################################################################
 
 #MAKE=		make
@@ -773,7 +782,8 @@ tzselect:	tzselect.ksh version
 		chmod +x $@.out
 		mv $@.out $@
 
-check:		check_character_set check_white_space check_links \
+check: check_back check_mild
+check_mild:	check_character_set check_white_space check_links \
 		  check_name_lengths check_slashed_abbrs check_sorted \
 		  check_tables check_web check_ziguard check_zishrink check_tzs
 
@@ -824,16 +834,19 @@ check_slashed_abbrs: $(TDATA_TO_CHECK)
 CHECK_CC_LIST = { n = split($$1,a,/,/); for (i=2; i<=n; i++) print a[1], a[i]; }
 
 check_sorted: backward backzone iso3166.tab zone.tab zone1970.tab
-		$(AWK) '/^Link/ {printf "%.5d %s\n", g, $$3} /^$$/ {g++}' \
+		$(AWK) '/^Link/ {printf "%.5d %s\n", g, $$3} !/./ {g++}' \
 		  backward | LC_ALL=C sort -cu
 		$(AWK) '/^Zone/ {print $$2}' backzone | LC_ALL=C sort -cu
 		touch $@
 
-check_links:	checklinks.awk $(TDATA_TO_CHECK) tzdata.zi
+check_back:	checklinks.awk $(TDATA_TO_CHECK)
 		$(AWK) \
 		  -v DATAFORM=$(DATAFORM) \
 		  -v backcheck=backward \
 		  -f checklinks.awk $(TDATA_TO_CHECK)
+		touch $@
+
+check_links:	checklinks.awk tzdata.zi
 		$(AWK) \
 		  -v DATAFORM=$(DATAFORM) \
 		  -f checklinks.awk tzdata.zi
@@ -849,7 +862,7 @@ check_tables:	checktab.awk $(YDATA) backward $(ZONETABLES)
 
 check_tzs:	$(TZS) $(TZS_NEW)
 		if test -s $(TZS); then \
-		  diff -u $(TZS) $(TZS_NEW); \
+		  $(DIFF_TZS) $(TZS) $(TZS_NEW); \
 		else \
 		  cp $(TZS_NEW) $(TZS); \
 		fi
@@ -1050,7 +1063,7 @@ $(TIME_T_ALTERNATIVES): $(VERSION_DEPS)
 		      TZS_YEAR="$$range" TZS_CUTOFF_FLAG="-t $$range" \
 			D=$$wd/$@.dir \
 		      to$$range.tzs) && \
-		  diff -u $(TIME_T_ALTERNATIVES_HEAD).dir/to$$range.tzs \
+		  $(DIFF_TZS) $(TIME_T_ALTERNATIVES_HEAD).dir/to$$range.tzs \
 			  $@.dir/to$$range.tzs && \
 		  if diff -q Makefile Makefile 2>/dev/null; then \
 		    quiet_option='-q'; \
@@ -1220,7 +1233,7 @@ zdump.o:	version.h
 zic.o:		private.h tzfile.h version.h
 
 .PHONY: ALL INSTALL all
-.PHONY: check check_time_t_alternatives
+.PHONY: check check_mild check_time_t_alternatives
 .PHONY: check_web check_zishrink
 .PHONY: clean clean_misc dummy.zd force_tzs
 .PHONY: install install_data maintainer-clean names

diff --git a/NEWS b/NEWS
@@ -1,5 +1,91 @@
 News for the tz database
 
+Release 2022g - 2022-11-29 08:58:31 -0800
+
+  Briefly:
+    The northern edge of Chihuahua changes to US timekeeping.
+    Much of Greenland stops changing clocks after March 2023.
+    Fix some pre-1996 timestamps in northern Canada.
+    C89 is now deprecated; please use C99 or later.
+    Portability fixes for AIX, libintl, MS-Windows, musl, z/OS
+    In C code, use more C23 features if available.
+    C23 timegm now supported by default
+    Fixes for unlikely integer overflows
+
+  Changes to future timestamps
+
+    In the Mexican state of Chihuahua, the border strip near the US
+    will change to agree with nearby US locations on 2022-11-30.
+    The strip's western part, represented by Ciudad Juárez, switches
+    from -06 all year to -07/-06 with US DST rules, like El Paso, TX.
+    The eastern part, represented by Ojinaga, will observe US DST next
+    year, like Presidio, TX.  (Thanks to Heitor David Pinto.)
+    A new Zone America/Ciudad_Juarez splits from America/Ojinaga.
+
+    Much of Greenland, represented by America/Nuuk, stops observing
+    winter time after March 2023, so its daylight saving time becomes
+    standard time.  (Thanks to Jonas Nyrup and Jürgen Appel.)
+
+  Changes to past timestamps
+
+    Changes for pre-1996 northern Canada (thanks to Chris Walton):
+
+      Merge America/Iqaluit and America/Pangnirtung into the former,
+      with a backward compatibility link for the latter name.
+      There is no good evidence the two locations differ since 1970.
+      This change affects pre-1996 America/Pangnirtung timestamps.
+
+      Cambridge Bay, Inuvik, Iqaluit, Rankin Inlet, Resolute and
+      Yellowknife did not observe DST in 1965, and did observe DST
+      from 1972 through 1979.
+
+      Whitehorse moved from -09 to -08 on 1966-02-27, not 1967-05-28.
+
+    Colombia's 1993 fallback was 02-06 24:00, not 04-04 00:00.
+    (Thanks to Alois Treindl.)
+
+    Singapore's 1981-12-31 change was at 16:00 UTC (23:30 local time),
+    not 24:00 local time.  (Thanks to Geoff Clare via Robert Elz.)
+
+  Changes to code
+
+    Although tzcode still works with C89, bugs found in recent routine
+    maintenance indicate that bitrot has set in and that in practice
+    C89 is no longer used to build tzcode.  As it is a maintenance
+    burden, support for C89 is planned to be removed soon.  Instead,
+    please use compilers compatible with C99, C11, C17, or C23.
+
+    timegm, which tzcode implemented in 1989, will finally be
+    standardized 34 years later as part of C23, so timegm is now
+    supported even if STD_INSPIRED is not defined.
+
+    Fix bug in zdump's tzalloc emulation on hosts that lack tm_zone.
+    (Problem reported by Đoàn Trần Công Danh.)
+
+    Fix bug in zic on hosts where malloc(0) yields NULL on success.
+    (Problem reported by Tim McBrayer for AIX 6.1.)
+
+    Fix zic configuration to avoid linkage failures on some platforms.
+    (Problems reported by Gilmore Davidson and Igor Ivanov.)
+
+    Work around MS-Windows nmake incompatibility with POSIX.
+    (Problem reported by Manuela Friedrich.)
+
+    Port mktime and strftime to debugging platforms where accessing
+    uninitialized data has undefined behavior (strftime problem
+    reported by Robert Elz).
+
+    Check more carefully for unlikely integer overflows, preferring
+    C23 <stdckdint.h> to overflow checking by hand, as the latter has
+    had obscure bugs.
+
+  Changes to build procedure
+
+    New Makefile rule check_mild that skips checking whether Link
+    lines are in the file 'backward'.  (Inspired by a suggestion from
+    Stephen Colebourne.)
+
+
 Release 2022f - 2022-10-28 18:04:57 -0700
 
   Briefly:
@@ -16,14 +102,15 @@ Release 2022f - 2022-10-28 18:04:57 -0700
     In C code, use some C23 features if available.
     Remove no-longer-needed workaround for Qt bug 53071.
 
-  Changes to future timestamps.
+  Changes to future timestamps
 
     Mexico will no longer observe DST after 2022, except for areas
     near the US border that continue to observe US DST rules.
     On 2022-10-30 at 02:00 the Mexican state of Chihuahua moves
     from -07 (-06 with DST) to year-round -06, thus not changing
     its clocks that day.  The new law states that Chihuahua
     near the US border no longer observes US DST.
+    (Thanks to gera for the heads-up about Chihuahua.)
 
     Fiji will not observe DST in 2022/3.  (Thanks to Shalvin Narayan.)
     For now, assume DST is suspended indefinitely.

diff --git a/africa b/africa
@@ -588,6 +588,10 @@ Zone Indian/Mauritius	3:50:00 -	LMT	1907 # Port Louis
 # Agalega Is, Rodriguez
 # no information; probably like Indian/Mauritius
 
+
+# Morocco
+# See Africa/Ceuta for Spanish Morocco.
+
 # From Alex Krivenyshev (2008-05-09):
 # Here is an article that Morocco plan to introduce Daylight Saving Time between
 # 1 June, 2008 and 27 September, 2008.

diff --git a/asia b/asia
@@ -3585,7 +3585,7 @@ Zone	Asia/Singapore	6:55:25 -	LMT	1901 Jan  1
 			7:20	-	+0720	1941 Sep  1
 			7:30	-	+0730	1942 Feb 16
 			9:00	-	+09	1945 Sep 12
-			7:30	-	+0730	1982 Jan  1
+			7:30	-	+0730	1981 Dec 31 16:00u
 			8:00	-	+08
 
 # Spratly Is

diff --git a/backward b/backward
@@ -267,6 +267,7 @@ Link	America/Tijuana		America/Ensenada
 Link	America/Indiana/Indianapolis	America/Fort_Wayne
 Link	America/Toronto		America/Montreal
 Link	America/Toronto		America/Nipigon
+Link	America/Iqaluit		America/Pangnirtung
 Link	America/Rio_Branco	America/Porto_Acre
 Link	America/Winnipeg	America/Rainy_River
 Link	America/Argentina/Cordoba	America/Rosario

diff --git a/backzone b/backzone
@@ -7,6 +7,10 @@
 # tz@iana.org for general use in the future).  For more, please see
 # the file CONTRIBUTING in the tz distribution.
 
+# When proposing changes to this file, please use 'git format-patch'
+# format, either by attaching the resulting .patch file to your email,
+# or by using 'git send-email'.  This will help maintainers save time.
+
 
 # From Paul Eggert (2014-10-31):
 
@@ -750,6 +754,55 @@ Zone America/Nipigon	-5:53:04 -	LMT	1895
 			-5:00	1:00	EDT	1942 Feb  9  2:00s
 			-5:00	Canada	E%sT
 
+# From Rives McDow (1999-11-08):
+# On October 31, when the rest of Nunavut went to Central time,
+# Pangnirtung wobbled.  Here is the result of their wobble:
+#
+# The following businesses and organizations in Pangnirtung use Central Time:
+#
+#	First Air, Power Corp, Nunavut Construction, Health Center, RCMP,
+#	Eastern Arctic National Parks, A & D Specialist
+#
+# The following businesses and organizations in Pangnirtung use Eastern Time:
+#
+#	Hamlet office, All other businesses, Both schools, Airport operator
+#
+# This has made for an interesting situation there, which warranted the news.
+# No one there that I spoke with seems concerned, or has plans to
+# change the local methods of keeping time, as it evidently does not
+# really interfere with any activities or make things difficult locally.
+# They plan to celebrate New Year's turn-over twice, one hour apart,
+# so it appears that the situation will last at least that long.
+# The Nunavut Intergovernmental Affairs hopes that they will "come to
+# their senses", but the locals evidently don't see any problem with
+# the current state of affairs.
+
+# From Michaela Rodrigue, writing in the
+# Nunatsiaq News (1999-11-19):
+# http://www.nunatsiaqonline.ca/archives/nunavut991130/nvt91119_17.html
+# Clyde River, Pangnirtung and Sanikiluaq now operate with two time zones,
+# central - or Nunavut time - for government offices, and eastern time
+# for municipal offices and schools....  Igloolik [was similar but then]
+# made the switch to central time on Saturday, Nov. 6.
+
+# From Chris Walton (2022-11-06):
+# The implication is that Pangnirtung and Qikiqtarjuaq have observed Eastern
+# Time as far back as 1984 (and likely even further back than that).
+# It is possible that these communities never actually observed Atlantic
+# Time, but that would be difficult to prove.
+# From Paul Eggert (2022-11-06):
+# This is in 'backzone' as we have no good evidence that Pangnirtung differs
+# from America/Iqaluit since 1970.  A Google Books snippet view of
+# volume 2, page 186 of "Pilot of Arctic Canada", published 1959 by
+# the Canadian Hydrographic Service, suggests (though does not state)
+# that Pangnirtung observed EST then.
+#
+# aka Panniqtuuq
+Zone America/Pangnirtung 0	-	-00	1921 # trading post est.
+			-5:00	NT_YK	E%sT	1999 Oct 31  2:00
+			-6:00	Canada	C%sT	2000 Oct 29  2:00
+			-5:00	Canada	E%sT
+
 # United States
 #
 # From Paul Eggert (2018-03-18):
@@ -1043,7 +1096,7 @@ Zone Asia/Kuala_Lumpur	6:46:46 -	LMT	1901 Jan  1
 			7:20	-	+0720	1941 Sep  1
 			7:30	-	+0730	1942 Feb 16
 			9:00	-	+09	1945 Sep 12
-			7:30	-	+0730	1982 Jan  1
+			7:30	-	+0730	1981 Dec 31 16:00u
 			8:00	-	+08
 
 # Kuwait

diff --git a/date.1 b/date.1
@@ -1,10 +1,12 @@
-.TH DATE 1
+.\" This file is in the public domain, so clarified as of
+.\" 2009-05-17 by Arthur David Olson.
+.TH date 1
 .SH NAME
 date \- show and set date and time
 .SH SYNOPSIS
 .if n .nh
 .if n .na
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
 .el .ds - \-
 .B date
 [
@@ -163,5 +165,3 @@ If
 is absent,
 UTC leap seconds are loaded from
 .BR /usr/share/zoneinfo/posixrules .
-.\" This file is in the public domain, so clarified as of
-.\" 2009-05-17 by Arthur David Olson.
diff --git a/date.c b/date.c
@@ -42,7 +42,7 @@ static void		display(const char *, time_t);
 static void		dogmt(void);
 static void		errensure(void);
 static void		timeout(FILE *, const char *, const struct tm *);
-static _Noreturn void	usage(void);
+static ATTRIBUTE_NORETURN void usage(void);
 
 int
 main(const int argc, char *argv[])
@@ -117,14 +117,19 @@ dogmt(void)
 	static char **	fakeenv;
 
 	if (fakeenv == NULL) {
-		register int	from;
-		register int	to;
-		register int	n;
 		static char	tzeutc0[] = "TZ=UTC0";
+		ptrdiff_t from, to, n;
 
 		for (n = 0;  environ[n] != NULL;  ++n)
 			continue;
-		fakeenv = malloc((n + 2) * sizeof *fakeenv);
+#if defined ckd_add && defined ckd_mul
+		if (!ckd_add(&n, n, 2) && !ckd_mul(&n, n, sizeof *fakeenv)
+		    && n <= SIZE_MAX)
+		  fakeenv = malloc(n);
+#else
+		if (n <= min(PTRDIFF_MAX, SIZE_MAX) / sizeof *fakeenv - 2)
+		  fakeenv = malloc((n + 2) * sizeof *fakeenv);
+#endif
 		if (fakeenv == NULL) {
 			fprintf(stderr, _("date: Memory exhausted\n"));
 			errensure();
@@ -183,33 +188,28 @@ display(char const *format, time_t now)
 static void
 timeout(FILE *fp, char const *format, struct tm const *tmp)
 {
-	char *	cp;
+	char *cp = NULL;
-	size_t	result;
+	ptrdiff_t result;
-	size_t	size;
+	ptrdiff_t size = 1024 / 2;
-	struct tm tm;
-	int INCR = 1024;
 
-	if (!tmp) {
-		fprintf(stderr, _("date: error: time out of range\n"));
-		errensure();
-		return;
-	}
-	tm = *tmp;
-	tmp = &tm;
-	size = INCR;
-	cp = malloc(size);
 	for ( ; ; ) {
-		if (cp == NULL) {
+#ifdef ckd_mul
+		bool bigger = !ckd_mul(&size, size, 2) && size <= SIZE_MAX;
+#else
+		bool bigger = (size <= min(PTRDIFF_MAX, SIZE_MAX) / 2
+			       && (size *= 2, true));
+#endif
+		char *newcp = bigger ? realloc(cp, size) : NULL;
+		if (!newcp) {
 			fprintf(stderr,
 				_("date: error: can't get memory\n"));
 			errensure();
 			exit(retval);
 		}
+		cp = newcp;
 		result = strftime(cp, size, format, tmp);
 		if (result != 0)
 			break;
-		size += INCR;
-		cp = realloc(cp, size);
 	}
 	fwrite(cp + 1, 1, result - 1, fp);
 	free(cp);

diff --git a/europe b/europe
@@ -1103,7 +1103,30 @@ Zone Atlantic/Faroe	-0:27:04 -	LMT	1908 Jan 11 # Tórshavn
 # "National Park" by Executive Order:
 # http://naalakkersuisut.gl/~/media/Nanoq/Files/Attached%20Files/Engelske-tekster/Legislation/Executive%20Order%20National%20Park.rtf
 # It is their only National Park.
-#
+
+# From Jonas Nyrup (2022-11-24):
+# On last Saturday in October 2023 when DST ends America/Nuuk will switch
+# from -03/-02 to -02/-01
+# https://sermitsiaq.ag/forslagtidsforskel-danmark-mindskes-sommertid-beholdes
+# ...
+# https://sermitsiaq.ag/groenland-skifte-tidszone-trods-bekymringer
+#
+# From Jürgen Appel (2022-11-25):
+# https://ina.gl/samlinger/oversigt-over-samlinger/samling/dagsordener/dagsorden.aspx?lang=da&day=24-11-2022
+# If I understand this correctly, from the next planned switch to
+# summer time, Greenland will permanently stay at that time, i.e. no
+# switch back to winter time in 2023 will occur.
+#
+# From Paul Eggert (2022-11-28):
+# The official document in Danish
+# https://naalakkersuisut.gl/-/media/naalakkersuisut/filer/kundgoerelser/2022/11/2511/31_da_inatsisartutlov-om-tidens-bestemmelse.pdf?la=da&hash=A33597D8A38CC7038465241119EF34F3
+# says standard time for Greenland is -02, that Naalakkersuisut can lay down
+# rules for DST and can require some areas to use a different time zone,
+# and that this all takes effect 2023-03-25 22:00.  The abovementioned
+# "bekymringer" URL says the intent is no transition March 25, that
+# Greenland will not go back to winter time in fall 2023, and that
+# only America/Nuuk is affected (though further changes may occur).
+
 # Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Thule	1991	1992	-	Mar	lastSun	2:00	1:00	D
 Rule	Thule	1991	1992	-	Sep	lastSun	2:00	0	S
@@ -1126,7 +1149,8 @@ Zone America/Scoresbysund -1:27:52 -	LMT	1916 Jul 28 # Ittoqqortoormiit
 			-1:00	EU	-01/+00
 Zone America/Nuuk	-3:26:56 -	LMT	1916 Jul 28 # Godthåb
 			-3:00	-	-03	1980 Apr  6  2:00
-			-3:00	EU	-03/-02
+			-3:00	EU	-03/-02	2023 Mar 25 22:00
+			-2:00	-	-02
 Zone America/Thule	-4:35:08 -	LMT	1916 Jul 28 # Pituffik
 			-4:00	Thule	A%sT
 

diff --git a/iso3166.tab b/iso3166.tab
@@ -3,13 +3,13 @@
 # This file is in the public domain, so clarified as of
 # 2009-05-17 by Arthur David Olson.
 #
-# From Paul Eggert (2015-05-02):
+# From Paul Eggert (2022-11-18):
 # This file contains a table of two-letter country codes.  Columns are
 # separated by a single tab.  Lines beginning with '#' are comments.
 # All text uses UTF-8 encoding.  The columns of the table are as follows:
 #
 # 1.  ISO 3166-1 alpha-2 country code, current as of
-#     ISO 3166-1 N976 (2018-11-06).  See: Updates on ISO 3166-1
+#     ISO 3166-1 N1087 (2022-09-02).  See: Updates on ISO 3166-1
 #     https://isotc.iso.org/livelink/livelink/Open/16944257
 # 2.  The usual English name for the coded region,
 #     chosen so that alphabetic sorting of subsets produces helpful lists.
@@ -238,7 +238,7 @@ SY	Syria
 SZ	Eswatini (Swaziland)
 TC	Turks & Caicos Is
 TD	Chad
-TF	French Southern & Antarctic Lands
+TF	French Southern Territories
 TG	Togo
 TH	Thailand
 TJ	Tajikistan

diff --git a/localtime.c b/localtime.c
@@ -425,8 +425,7 @@ tzloadbody(char const *name, struct state *sp, bool doextend,
 #endif
 	if (!doaccess) {
 		char const *dot;
-		size_t namelen = strlen(name);
+		if (sizeof lsp->fullname - sizeof tzdirslash <= strlen(name))
-		if (sizeof lsp->fullname - sizeof tzdirslash <= namelen)
 		  return ENAMETOOLONG;
 
 		/* Create a string "TZDIR/NAME".  Using sprintf here
@@ -839,7 +838,7 @@ is_digit(char c)
 ** Return a pointer to that character.
 */
 
-static ATTRIBUTE_PURE const char *
+static ATTRIBUTE_REPRODUCIBLE const char *
 getzname(register const char *strp)
 {
 	register char	c;
@@ -860,7 +859,7 @@ getzname(register const char *strp)
 ** We don't do any checking here; checking is done later in common-case code.
 */
 
-static ATTRIBUTE_PURE const char *
+static ATTRIBUTE_REPRODUCIBLE const char *
 getqzname(register const char *strp, const int delim)
 {
 	register int	c;
@@ -1120,13 +1119,11 @@ tzparse(const char *name, struct state *sp, struct state *basep)
 {
 	const char *			stdname;
 	const char *			dstname;
-	size_t				stdlen;
-	size_t				dstlen;
-	size_t				charcnt;
 	int_fast32_t			stdoffset;
 	int_fast32_t			dstoffset;
 	register char *			cp;
 	register bool			load_ok;
+	ptrdiff_t stdlen, dstlen, charcnt;
 	time_t atlo = TIME_T_MIN, leaplo = TIME_T_MIN;
 
 	stdname = name;
@@ -1568,6 +1565,14 @@ localsub(struct state const *sp, time_t const *timep, int_fast32_t setname,
 					return NULL;	/* "cannot happen" */
 			result = localsub(sp, &newt, setname, tmp);
 			if (result) {
+#if defined ckd_add && defined ckd_sub
+				if (t < sp->ats[0]
+				    ? ckd_sub(&result->tm_year,
+					      result->tm_year, years)
+				    : ckd_add(&result->tm_year,
+					      result->tm_year, years))
+				  return NULL;
+#else
 				register int_fast64_t newy;
 
 				newy = result->tm_year;
@@ -1577,6 +1582,7 @@ localsub(struct state const *sp, time_t const *timep, int_fast32_t setname,
 				if (! (INT_MIN <= newy && newy <= INT_MAX))
 					return NULL;
 				result->tm_year = newy;
+#endif
 			}
 			return result;
 	}
@@ -1656,8 +1662,8 @@ localtime_r(const time_t *timep, struct tm *tmp)
 */
 
 static struct tm *
-gmtsub(struct state const *sp, time_t const *timep, int_fast32_t offset,
+gmtsub(ATTRIBUTE_MAYBE_UNUSED struct state const *sp, time_t const *timep,
-       struct tm *tmp)
+       int_fast32_t offset, struct tm *tmp)
 {
 	register struct tm *	result;
 
@@ -1786,6 +1792,12 @@ timesub(const time_t *timep, int_fast32_t offset,
 		y = newy;
 	}
 
+#ifdef ckd_add
+	if (ckd_add(&tmp->tm_year, y, -TM_YEAR_BASE)) {
+	  errno = EOVERFLOW;
+	  return NULL;
+	}
+#else
 	if (!TYPE_SIGNED(time_t) && y < TM_YEAR_BASE) {
 	  int signed_y = y;
 	  tmp->tm_year = signed_y - TM_YEAR_BASE;
@@ -1796,6 +1808,7 @@ timesub(const time_t *timep, int_fast32_t offset,
 	  errno = EOVERFLOW;
 	  return NULL;
 	}
+#endif
 	tmp->tm_yday = idays;
 	/*
 	** The "extra" mods below avoid overflow problems.
@@ -1870,6 +1883,9 @@ ctime_r(const time_t *timep, char *buf)
 static bool
 increment_overflow(int *ip, int j)
 {
+#ifdef ckd_add
+	return ckd_add(ip, *ip, j);
+#else
 	register int const	i = *ip;
 
 	/*
@@ -1882,22 +1898,30 @@ increment_overflow(int *ip, int j)
 		return true;
 	*ip += j;
 	return false;
+#endif
 }
 
 static bool
 increment_overflow32(int_fast32_t *const lp, int const m)
 {
+#ifdef ckd_add
+	return ckd_add(lp, *lp, m);
+#else
 	register int_fast32_t const	l = *lp;
 
 	if ((l >= 0) ? (m > INT_FAST32_MAX - l) : (m < INT_FAST32_MIN - l))
 		return true;
 	*lp += m;
 	return false;
+#endif
 }
 
 static bool
 increment_overflow_time(time_t *tp, int_fast32_t j)
 {
+#ifdef ckd_add
+	return ckd_add(tp, *tp, j);
+#else
 	/*
 	** This is like
 	** 'if (! (TIME_T_MIN <= *tp + j && *tp + j <= TIME_T_MAX)) ...',
@@ -1909,6 +1933,7 @@ increment_overflow_time(time_t *tp, int_fast32_t j)
 		return true;
 	*tp += j;
 	return false;
+#endif
 }
 
 static bool
@@ -1951,6 +1976,23 @@ tmcomp(register const struct tm *const atmp,
 	return result;
 }
 
+/* Copy to *DEST from *SRC.  Copy only the members needed for mktime,
+   as other members might not be initialized.  */
+static void
+mktmcpy(struct tm *dest, struct tm const *src)
+{
+  dest->tm_sec = src->tm_sec;
+  dest->tm_min = src->tm_min;
+  dest->tm_hour = src->tm_hour;
+  dest->tm_mday = src->tm_mday;
+  dest->tm_mon = src->tm_mon;
+  dest->tm_year = src->tm_year;
+  dest->tm_isdst = src->tm_isdst;
+#if defined TM_GMTOFF && ! UNINIT_TRAP
+  dest->TM_GMTOFF = src->TM_GMTOFF;
+#endif
+}
+
 static time_t
 time2sub(struct tm *const tmp,
 	 struct tm *(*funcp)(struct state const *, time_t const *,
@@ -1972,7 +2014,8 @@ time2sub(struct tm *const tmp,
 	struct tm			yourtm, mytm;
 
 	*okayp = false;
-	yourtm = *tmp;
+	mktmcpy(&yourtm, tmp);
+
 	if (do_norm_secs) {
 		if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
 			SECSPERMIN))
@@ -2014,14 +2057,19 @@ time2sub(struct tm *const tmp,
 				return WRONG;
 		}
 	}
+#ifdef ckd_add
+	if (ckd_add(&yourtm.tm_year, y, -TM_YEAR_BASE))
+	  return WRONG;
+#else
 	if (increment_overflow32(&y, -TM_YEAR_BASE))
 		return WRONG;
 	if (! (INT_MIN <= y && y <= INT_MAX))
 		return WRONG;
 	yourtm.tm_year = y;
+#endif
 	if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN)
 		saved_seconds = 0;
-	else if (y + TM_YEAR_BASE < EPOCH_YEAR) {
+	else if (yourtm.tm_year < EPOCH_YEAR - TM_YEAR_BASE) {
 		/*
 		** We can't set tm_sec to 0, because that might push the
 		** time below the minimum representable time.
@@ -2278,21 +2326,16 @@ mktime(struct tm *tmp)
 }
 
 #ifdef STD_INSPIRED
-
 time_t
 timelocal(struct tm *tmp)
 {
 	if (tmp != NULL)
 		tmp->tm_isdst = -1;	/* in case it wasn't initialized */
 	return mktime(tmp);
 }
-
+#else
-time_t
+static
-timegm(struct tm *tmp)
+#endif
-{
-  return timeoff(tmp, 0);
-}
-
 time_t
 timeoff(struct tm *tmp, long offset)
 {
@@ -2302,7 +2345,18 @@ timeoff(struct tm *tmp, long offset)
   return time1(tmp, gmtsub, gmtptr, offset);
 }
 
-#endif /* defined STD_INSPIRED */
+time_t
+timegm(struct tm *tmp)
+{
+  time_t t;
+  struct tm tmcpy;
+  mktmcpy(&tmcpy, tmp);
+  tmcpy.tm_wday = -1;
+  t = timeoff(&tmcpy, 0);
+  if (0 <= tmcpy.tm_wday)
+    *tmp = tmcpy;
+  return t;
+}
 
 static int_fast32_t
 leapcorr(struct state const *sp, time_t t)

diff --git a/newctime.3 b/newctime.3
@@ -1,9 +1,11 @@
+.\" This file is in the public domain, so clarified as of
+.\" 2009-05-17 by Arthur David Olson.
 .TH NEWCTIME 3
 .SH NAME
 asctime, ctime, difftime, gmtime, localtime, mktime \- convert date and time
 .SH SYNOPSIS
 .nf
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
 .el .ds - \-
 .B #include <time.h>
 .PP
@@ -340,5 +342,3 @@ restricted to years in the range 1900 through 2099.
 To avoid this portability mess, new programs should use
 .B strftime
 instead.
-.\" This file is in the public domain, so clarified as of
-.\" 2009-05-17 by Arthur David Olson.
diff --git a/newstrftime.3 b/newstrftime.3
@@ -40,7 +40,7 @@
 strftime \- format date and time
 .SH SYNOPSIS
 .nf
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
 .el .ds - \-
 .B #include <time.h>
 .PP
@@ -55,7 +55,7 @@ strftime \- format date and time
 .ie '\(rq'' .ds rq \&"\"
 .el .ds rq \(rq\"
 .de c
-.ie \n(.g \f(CW\\$1\fP\\$2
+.ie \n(.g \f(CR\\$1\fP\\$2
 .el \\$1\\$2
 ..
 .de q

diff --git a/newtzset.3 b/newtzset.3
@@ -1,9 +1,11 @@
+.\" This file is in the public domain, so clarified as of
+.\" 2009-05-17 by Arthur David Olson.
 .TH NEWTZSET 3
 .SH NAME
 tzset \- initialize time conversion information
 .SH SYNOPSIS
 .nf
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
 .el .ds - \-
 .B #include <time.h>
 .PP
@@ -331,7 +333,7 @@ from the rest of the specification.
 .br
 /usr/share/zoneinfo/localtime	local timezone file
 .br
-/usr/share/zoneinfo/posixrules	used with POSIX-style TZ's
+/usr/share/zoneinfo/posixrules	used with POSIX-style TZ
 .br
 /usr/share/zoneinfo/GMT	for UTC leap seconds
 .sp
@@ -346,5 +348,3 @@ newctime(3),
 newstrftime(3),
 time(2),
 tzfile(5)
-.\" This file is in the public domain, so clarified as of
-.\" 2009-05-17 by Arthur David Olson.
diff --git a/northamerica b/northamerica
@@ -1969,6 +1969,37 @@ Zone America/Fort_Nelson	-8:10:47 -	LMT	1884
 
 # Northwest Territories, Nunavut, Yukon
 
+# From Chris Walton (2022-11-06):
+# Whitehorse Star - Thursday April 22, 1965 - page 1
+# title: DST Starts Monday ...
+# https://www.newspapers.com/image/578587481/
+# The title of this first article is wrong and/or misleading.
+# Also, the start time shown in the  article is vague; it simply says "after
+# midnight" when it probably should have stated 2:00a.m....
+#
+# Whitehorse Star - Monday October 25, 1965 - page 15 ...
+# https://www.newspapers.com/image/578589147/
+# The 1965 Yukon Council minutes can be found here:
+# http://assets.yukonarchives.ca/PER_YG_06_1965_C20_S02_v1.pdf
+# ... I do not currently believe that NWT touched any of its clocks in 1965....
+#
+# Whitehorse Star - Thursday Feb 24,1966 - page 2
+# title: It's Time for YDT ...
+# https://www.newspapers.com/image/578575979/ ...
+# America/Whitehorse as a permanent change from UTC-9(YST) to
+# UTC-8(PST) at 00:00 on Sunday February 27, 1966....
+#
+# Whitehorse Star - Friday April 28,1972 - page 6
+# title: Daylight Saving Time for N.W.T....
+# https://www.newspapers.com/image/578701610/ ...
+# Nunavut and NWT zones ... DST starting in 1972.... Start and End ...
+# should be the same as the rest of Canada
+#
+#
+# From Paul Eggert (2022-11-06):
+# For now, assume Yukon's 1965-04-22 spring forward was 00:00 -> 02:00, as this
+# seems likely than 02:00 -> 04:00 and matches "after midnight".
+
 # From Paul Eggert (2006-03-22):
 # Dawson switched to PST in 1973.  Inuvik switched to MST in 1979.
 # Mathew Englander (1996-10-07) gives the following refs:
@@ -2083,6 +2114,13 @@ Zone America/Fort_Nelson	-8:10:47 -	LMT	1884
 # * Interpretation Act, RSY 2002, c 125
 # https://www.canlii.org/en/yk/laws/stat/rsy-2002-c-125/latest/rsy-2002-c-125.html
 
+# From Chris Walton (2022-11-06):
+# The 5th edition of the Atlas of Canada contains a time zone map that
+# shows both legislated and observed time zone boundaries.
+# All communities on Baffin Island are shown to be observing Eastern time.
+# The date on the map is 1984.
+# https://ftp.maps.canada.ca/pub/nrcan_rncan/raster/atlas_5_ed/eng/other/referencemaps/mcr4056.pdf
+
 # From Rives McDow (1999-09-04):
 # Nunavut ... moved ... to incorporate the whole territory into one time zone.
 # Nunavut moves to single time zone Oct. 31
@@ -2095,40 +2133,7 @@ Zone America/Fort_Nelson	-8:10:47 -	LMT	1884
 # From Paul Eggert (1999-09-20):
 # Basic Facts: The New Territory
 # http://www.nunavut.com/basicfacts/english/basicfacts_1territory.html
-# (1999) reports that Pangnirtung operates on eastern time,
+# (1999) reports that ... Coral Harbour does not observe DST.
-# and that Coral Harbour does not observe DST.  We don't know when
-# Pangnirtung switched to eastern time; we'll guess 1995.
-
-# From Rives McDow (1999-11-08):
-# On October 31, when the rest of Nunavut went to Central time,
-# Pangnirtung wobbled.  Here is the result of their wobble:
-#
-# The following businesses and organizations in Pangnirtung use Central Time:
-#
-#	First Air, Power Corp, Nunavut Construction, Health Center, RCMP,
-#	Eastern Arctic National Parks, A & D Specialist
-#
-# The following businesses and organizations in Pangnirtung use Eastern Time:
-#
-#	Hamlet office, All other businesses, Both schools, Airport operator
-#
-# This has made for an interesting situation there, which warranted the news.
-# No one there that I spoke with seems concerned, or has plans to
-# change the local methods of keeping time, as it evidently does not
-# really interfere with any activities or make things difficult locally.
-# They plan to celebrate New Year's turn-over twice, one hour apart,
-# so it appears that the situation will last at least that long.
-# The Nunavut Intergovernmental Affairs hopes that they will "come to
-# their senses", but the locals evidently don't see any problem with
-# the current state of affairs.
-
-# From Michaela Rodrigue, writing in the
-# Nunatsiaq News (1999-11-19):
-# http://www.nunatsiaqonline.ca/archives/nunavut991130/nvt91119_17.html
-# Clyde River, Pangnirtung and Sanikiluaq now operate with two time zones,
-# central - or Nunavut time - for government offices, and eastern time
-# for municipal offices and schools....  Igloolik [was similar but then]
-# made the switch to central time on Saturday, Nov. 6.
 
 # From Paul Eggert (2000-10-02):
 # Matthews and Vincent (1998) say the following, but we lack histories
@@ -2287,18 +2292,12 @@ Rule	NT_YK	1919	only	-	Nov	 1	0:00	0	S
 Rule	NT_YK	1942	only	-	Feb	 9	2:00	1:00	W # War
 Rule	NT_YK	1945	only	-	Aug	14	23:00u	1:00	P # Peace
 Rule	NT_YK	1945	only	-	Sep	30	2:00	0	S
-Rule	NT_YK	1965	only	-	Apr	lastSun	0:00	2:00	DD
+Rule	NT_YK	1972	1986	-	Apr	lastSun	2:00	1:00	D
-Rule	NT_YK	1965	only	-	Oct	lastSun	2:00	0	S
+Rule	NT_YK	1972	2006	-	Oct	lastSun	2:00	0	S
-Rule	NT_YK	1980	1986	-	Apr	lastSun	2:00	1:00	D
-Rule	NT_YK	1980	2006	-	Oct	lastSun	2:00	0	S
 Rule	NT_YK	1987	2006	-	Apr	Sun>=1	2:00	1:00	D
+Rule	Yukon	1965	only	-	Apr	lastSun	0:00	2:00	DD
+Rule	Yukon	1965	only	-	Oct	lastSun	2:00	0	S
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
-# aka Panniqtuuq
-Zone America/Pangnirtung 0	-	-00	1921 # trading post est.
-			-4:00	NT_YK	A%sT	1995 Apr Sun>=1  2:00
-			-5:00	Canada	E%sT	1999 Oct 31  2:00
-			-6:00	Canada	C%sT	2000 Oct 29  2:00
-			-5:00	Canada	E%sT
 # formerly Frobisher Bay
 Zone America/Iqaluit	0	-	-00	1942 Aug # Frobisher Bay est.
 			-5:00	NT_YK	E%sT	1999 Oct 31  2:00
@@ -2331,13 +2330,15 @@ Zone America/Inuvik	0	-	-00	1953 # Inuvik founded
 			-7:00	NT_YK	M%sT	1980
 			-7:00	Canada	M%sT
 Zone America/Whitehorse	-9:00:12 -	LMT	1900 Aug 20
-			-9:00	NT_YK	Y%sT	1967 May 28  0:00
+			-9:00	NT_YK	Y%sT	1965
-			-8:00	NT_YK	P%sT	1980
+			-9:00	Yukon	Y%sT	1966 Feb 27  0:00
+			-8:00	-	PST	1980
 			-8:00	Canada	P%sT	2020 Nov  1
 			-7:00	-	MST
 Zone America/Dawson	-9:17:40 -	LMT	1900 Aug 20
-			-9:00	NT_YK	Y%sT	1973 Oct 28  0:00
+			-9:00	NT_YK	Y%sT	1965
-			-8:00	NT_YK	P%sT	1980
+			-9:00	Yukon	Y%sT	1973 Oct 28  0:00
+			-8:00	-	PST	1980
 			-8:00	Canada	P%sT	2020 Nov  1
 			-7:00	-	MST
 
@@ -2559,6 +2560,14 @@ Zone America/Dawson	-9:17:40 -	LMT	1900 Aug 20
 # This abolishes DST except where US DST rules are observed,
 # and in addition changes all of Chihuahua to -06 with no DST.
 
+# From Heitor David Pinto (2022-11-28):
+# Now the northern municipalities want to have the same time zone as the
+# respective neighboring cities in the US, for example Juárez in UTC-7 with
+# DST, matching El Paso, and Ojinaga in UTC-6 with DST, matching Presidio....
+# the president authorized the publication of the decree for November 29,
+# so the time change would occur on November 30 at 0:00.
+# http://puentelibre.mx/noticia/ciudad_juarez_cambio_horario_noviembre_2022/
+
 # Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Mexico	1931	only	-	May	1	23:00	1:00	D
 Rule	Mexico	1931	only	-	Oct	1	0:00	0	S
@@ -2590,14 +2599,12 @@ Zone America/Merida	-5:58:28 -	LMT	1922 Jan  1  6:00u
 			-6:00	Mexico	C%sT
 # Coahuila, Nuevo León, Tamaulipas (near US border)
 # This includes the following municipalities:
-#   in Coahuila: Ocampo, Acuña, Zaragoza, Jiménez, Piedras Negras, Nava,
+#   in Coahuila: Acuña, Allende, Guerrero, Hidalgo, Jiménez, Morelos, Nava,
-#     Guerrero, Hidalgo.
+#     Ocampo, Piedras Negras, Villa Unión, Zaragoza
-#   in Nuevo León: Anáhuac, Los Aldama.
+#   in Nuevo León: Anáhuac
 #   in Tamaulipas: Nuevo Laredo, Guerrero, Mier, Miguel Alemán, Camargo,
 #     Gustavo Díaz Ordaz, Reynosa, Río Bravo, Valle Hermoso, Matamoros.
-# See: Inicia mañana Horario de Verano en zona fronteriza, El Universal,
+# https://www.dof.gob.mx/nota_detalle.php?codigo=5670045&fecha=28/10/2022
-# 2016-03-12
-# http://www.eluniversal.com.mx/articulo/estados/2016/03/12/inicia-manana-horario-de-verano-en-zona-fronteriza
 Zone America/Matamoros	-6:30:00 -	LMT	1922 Jan  1  6:00u
 			-6:00	-	CST	1988
 			-6:00	US	C%sT	1989
@@ -2616,10 +2623,24 @@ Zone America/Mexico_City -6:36:36 -	LMT	1922 Jan  1  7:00u
 			-6:00	Mexico	C%sT	2001 Sep 30  2:00
 			-6:00	-	CST	2002 Feb 20
 			-6:00	Mexico	C%sT
-# Chihuahua (near US border)
+# Chihuahua (near US border - western side)
 # This includes the municipalities of Janos, Ascensión, Juárez, Guadalupe,
-# Práxedis G Guerrero, Coyame del Sotol, Ojinaga, and Manuel Benavides.
+# and Práxedis G Guerrero.
-# (See the 2016-03-12 El Universal source mentioned above.)
+# http://gaceta.diputados.gob.mx/PDF/65/2a022/nov/20221124-VII.pdf
+Zone America/Ciudad_Juarez -7:05:56 -	LMT	1922 Jan  1  7:00u
+			-7:00	-	MST	1927 Jun 10 23:00
+			-6:00	-	CST	1930 Nov 15
+			-7:00	Mexico	M%sT	1932 Apr  1
+			-6:00	-	CST	1996
+			-6:00	Mexico	C%sT	1998
+			-6:00	-	CST	1998 Apr Sun>=1  3:00
+			-7:00	Mexico	M%sT	2010
+			-7:00	US	M%sT	2022 Oct 30  2:00
+			-6:00	-	CST	2022 Nov 30  0:00
+			-7:00	US	M%sT
+# Chihuahua (near US border - eastern side)
+# The municipalities of Coyame del Sotol, Ojinaga, and Manuel Benavides.
+# http://gaceta.diputados.gob.mx/PDF/65/2a022/nov/20221124-VII.pdf
 Zone America/Ojinaga	-6:57:40 -	LMT	1922 Jan  1  7:00u
 			-7:00	-	MST	1927 Jun 10 23:00
 			-6:00	-	CST	1930 Nov 15
@@ -2629,7 +2650,8 @@ Zone America/Ojinaga	-6:57:40 -	LMT	1922 Jan  1  7:00u
 			-6:00	-	CST	1998 Apr Sun>=1  3:00
 			-7:00	Mexico	M%sT	2010
 			-7:00	US	M%sT	2022 Oct 30  2:00
-			-6:00	-	CST
+			-6:00	-	CST	2022 Nov 30  0:00
+			-6:00	US	C%sT
 # Chihuahua (away from US border)
 Zone America/Chihuahua	-7:04:20 -	LMT	1922 Jan  1  7:00u
 			-7:00	-	MST	1927 Jun 10 23:00
@@ -2651,6 +2673,18 @@ Zone America/Hermosillo	-7:23:52 -	LMT	1922 Jan  1  7:00u
 			-7:00	Mexico	M%sT	1999
 			-7:00	-	MST
 
+# Baja California Sur, Nayarit (except Bahía de Banderas), Sinaloa
+Zone America/Mazatlan	-7:05:40 -	LMT	1922 Jan  1  7:00u
+			-7:00	-	MST	1927 Jun 10 23:00
+			-6:00	-	CST	1930 Nov 15
+			-7:00	Mexico	M%sT	1932 Apr  1
+			-6:00	-	CST	1942 Apr 24
+			-7:00	-	MST	1949 Jan 14
+			-8:00	-	PST	1970
+			-7:00	Mexico	M%sT
+
+# Bahía de Banderas
+
 # From Alexander Krivenyshev (2010-04-21):
 # According to news, Bahía de Banderas (Mexican state of Nayarit)
 # changed time zone UTC-7 to new time zone UTC-6 on April 4, 2010 (to
@@ -2678,17 +2712,6 @@ Zone America/Hermosillo	-7:23:52 -	LMT	1922 Jan  1  7:00u
 # From Arthur David Olson (2010-05-01):
 # Use "Bahia_Banderas" to keep the name to fourteen characters.
 
-# Mazatlán
-Zone America/Mazatlan	-7:05:40 -	LMT	1922 Jan  1  7:00u
-			-7:00	-	MST	1927 Jun 10 23:00
-			-6:00	-	CST	1930 Nov 15
-			-7:00	Mexico	M%sT	1932 Apr  1
-			-6:00	-	CST	1942 Apr 24
-			-7:00	-	MST	1949 Jan 14
-			-8:00	-	PST	1970
-			-7:00	Mexico	M%sT
-
-# Bahía de Banderas
 Zone America/Bahia_Banderas -7:01:00 -	LMT	1922 Jan  1  7:00u
 			-7:00	-	MST	1927 Jun 10 23:00
 			-6:00	-	CST	1930 Nov 15

diff --git a/private.h b/private.h
@@ -17,6 +17,10 @@
 ** Thank you!
 */
 
+#ifndef __STDC_VERSION__
+# define __STDC_VERSION__ 0
+#endif
+
 /* Define true, false and bool if they don't work out of the box.  */
 #if __STDC_VERSION__ < 199901
 # define true 1
@@ -56,24 +60,13 @@
 # endif
 #endif
 /* _Generic is buggy in pre-4.9 GCC.  */
-#if !defined HAVE_GENERIC && defined __GNUC__
+#if !defined HAVE_GENERIC && defined __GNUC__ && !defined __STRICT_ANSI__
 # define HAVE_GENERIC (4 < __GNUC__ + (9 <= __GNUC_MINOR__))
 #endif
 #ifndef HAVE_GENERIC
 # define HAVE_GENERIC (201112 <= __STDC_VERSION__)
 #endif
 
-#if !defined HAVE_GETRANDOM && defined __has_include
-# if __has_include(<sys/random.h>)
-#  define HAVE_GETRANDOM true
-# else
-#  define HAVE_GETRANDOM false
-# endif
-#endif
-#ifndef HAVE_GETRANDOM
-# define HAVE_GETRANDOM (2 < __GLIBC__ + (25 <= __GLIBC_MINOR__))
-#endif
-
 #if !defined HAVE_GETTEXT && defined __has_include
 # if __has_include(<libintl.h>)
 #  define HAVE_GETTEXT true
@@ -289,36 +282,36 @@
 #endif
 
 /* Pre-C99 GCC compilers define __LONG_LONG_MAX__ instead of LLONG_MAX.  */
-#ifdef __LONG_LONG_MAX__
+#if defined __LONG_LONG_MAX__ && !defined __STRICT_ANSI__
 # ifndef LLONG_MAX
 #  define LLONG_MAX __LONG_LONG_MAX__
 # endif
 # ifndef LLONG_MIN
 #  define LLONG_MIN (-1 - LLONG_MAX)
 # endif
+# ifndef ULLONG_MAX
+#  define ULLONG_MAX (LLONG_MAX * 2ull + 1)
+# endif
 #endif
 
 #ifndef INT_FAST64_MAX
-# ifdef LLONG_MAX
+# if 1 <= LONG_MAX >> 31 >> 31
-typedef long long	int_fast64_t;
+typedef long int_fast64_t;
-#  define INT_FAST64_MIN LLONG_MIN
-#  define INT_FAST64_MAX LLONG_MAX
-# else
-#  if LONG_MAX >> 31 < 0xffffffff
-Please use a compiler that supports a 64-bit integer type (or wider);
-you may need to compile with "-DHAVE_STDINT_H".
-#  endif
-typedef long		int_fast64_t;
 #  define INT_FAST64_MIN LONG_MIN
 #  define INT_FAST64_MAX LONG_MAX
+# else
+/* If this fails, compile with -DHAVE_STDINT_H or with a better compiler.  */
+typedef long long int_fast64_t;
+#  define INT_FAST64_MIN LLONG_MIN
+#  define INT_FAST64_MAX LLONG_MAX
 # endif
 #endif
 
 #ifndef PRIdFAST64
-# if INT_FAST64_MAX == LLONG_MAX
+# if INT_FAST64_MAX == LONG_MAX
-#  define PRIdFAST64 "lld"
-# else
 #  define PRIdFAST64 "ld"
+# else
+#  define PRIdFAST64 "lld"
 # endif
 #endif
 
@@ -364,32 +357,35 @@ typedef long intmax_t;
 # endif
 #endif
 
+#ifndef PTRDIFF_MAX
+# define PTRDIFF_MAX MAXVAL(ptrdiff_t, TYPE_BIT(ptrdiff_t))
+#endif
+
 #ifndef UINT_FAST32_MAX
 typedef unsigned long uint_fast32_t;
 #endif
 
 #ifndef UINT_FAST64_MAX
-# if defined ULLONG_MAX || defined __LONG_LONG_MAX__
+# if 3 <= ULONG_MAX >> 31 >> 31
-typedef unsigned long long uint_fast64_t;
+typedef unsigned long uint_fast64_t;
+#  define UINT_FAST64_MAX ULONG_MAX
 # else
-#  if ULONG_MAX >> 31 >> 1 < 0xffffffff
+/* If this fails, compile with -DHAVE_STDINT_H or with a better compiler.  */
-Please use a compiler that supports a 64-bit integer type (or wider);
+typedef unsigned long long uint_fast64_t;
-you may need to compile with "-DHAVE_STDINT_H".
+#  define UINT_FAST64_MAX ULLONG_MAX
-#  endif
-typedef unsigned long	uint_fast64_t;
 # endif
 #endif
 
 #ifndef UINTMAX_MAX
-# if defined ULLONG_MAX || defined __LONG_LONG_MAX__
+# ifdef ULLONG_MAX
 typedef unsigned long long uintmax_t;
 # else
 typedef unsigned long uintmax_t;
 # endif
 #endif
 
 #ifndef PRIuMAX
-# if defined ULLONG_MAX || defined __LONG_LONG_MAX__
+# ifdef ULLONG_MAX
 #  define PRIuMAX "llu"
 # else
 #  define PRIuMAX "lu"
@@ -400,23 +396,114 @@ typedef unsigned long uintmax_t;
 # define SIZE_MAX ((size_t) -1)
 #endif
 
+/* Support ckd_add, ckd_sub, ckd_mul on C23 or recent-enough GCC-like
+   hosts, unless compiled with -DHAVE_STDCKDINT_H=0 or with pre-C23 EDG.  */
+#if !defined HAVE_STDCKDINT_H && defined __has_include
+# if __has_include(<stdckdint.h>)
+#  define HAVE_STDCKDINT_H true
+# endif
+#endif
+#ifdef HAVE_STDCKDINT_H
+# if HAVE_STDCKDINT_H
+#  include <stdckdint.h>
+# endif
+#elif defined __EDG__
+/* Do nothing, to work around EDG bug <https://bugs.gnu.org/53256>.  */
+#elif defined __has_builtin
+# if __has_builtin(__builtin_add_overflow)
+#  define ckd_add(r, a, b) __builtin_add_overflow(a, b, r)
+# endif
+# if __has_builtin(__builtin_sub_overflow)
+#  define ckd_sub(r, a, b) __builtin_sub_overflow(a, b, r)
+# endif
+# if __has_builtin(__builtin_mul_overflow)
+#  define ckd_mul(r, a, b) __builtin_mul_overflow(a, b, r)
+# endif
+#elif 7 <= __GNUC__
+# define ckd_add(r, a, b) __builtin_add_overflow(a, b, r)
+# define ckd_sub(r, a, b) __builtin_sub_overflow(a, b, r)
+# define ckd_mul(r, a, b) __builtin_mul_overflow(a, b, r)
+#endif
+
 #if 3 <= __GNUC__
-# define ATTRIBUTE_CONST __attribute__((const))
+# define ATTRIBUTE_MALLOC __attribute__((malloc))
-# define ATTRIBUTE_MALLOC __attribute__((__malloc__))
+# define ATTRIBUTE_FORMAT(spec) __attribute__((format spec))
-# define ATTRIBUTE_PURE __attribute__((__pure__))
-# define ATTRIBUTE_FORMAT(spec) __attribute__((__format__ spec))
 #else
-# define ATTRIBUTE_CONST /* empty */
 # define ATTRIBUTE_MALLOC /* empty */
-# define ATTRIBUTE_PURE /* empty */
 # define ATTRIBUTE_FORMAT(spec) /* empty */
 #endif
 
-#if !defined _Noreturn && __STDC_VERSION__ < 201112
+#if (defined __has_c_attribute \
-# if 2 < __GNUC__ + (8 <= __GNUC_MINOR__)
+     && (202311 <= __STDC_VERSION__ || !defined __STRICT_ANSI__))
-#  define _Noreturn __attribute__((__noreturn__))
+# define HAVE_HAS_C_ATTRIBUTE true
+#else
+# define HAVE_HAS_C_ATTRIBUTE false
+#endif
+
+#if HAVE_HAS_C_ATTRIBUTE
+# if __has_c_attribute(fallthrough)
+#  define ATTRIBUTE_FALLTHROUGH [[fallthrough]]
+# endif
+#endif
+#ifndef ATTRIBUTE_FALLTHROUGH
+# if 7 <= __GNUC__
+#  define ATTRIBUTE_FALLTHROUGH __attribute__((fallthrough))
+# else
+#  define ATTRIBUTE_FALLTHROUGH ((void) 0)
+# endif
+#endif
+
+#if HAVE_HAS_C_ATTRIBUTE
+# if __has_c_attribute(maybe_unused)
+#  define ATTRIBUTE_MAYBE_UNUSED [[maybe_unused]]
+# endif
+#endif
+#ifndef ATTRIBUTE_MAYBE_UNUSED
+# if 2 < __GNUC__ + (7 <= __GNUC_MINOR__)
+#  define ATTRIBUTE_MAYBE_UNUSED __attribute__((unused))
+# else
+#  define ATTRIBUTE_MAYBE_UNUSED /* empty */
+# endif
+#endif
+
+#if HAVE_HAS_C_ATTRIBUTE
+# if __has_c_attribute(noreturn)
+#  define ATTRIBUTE_NORETURN [[noreturn]]
+# endif
+#endif
+#ifndef ATTRIBUTE_NORETURN
+# if 201112 <= __STDC_VERSION__
+#  define ATTRIBUTE_NORETURN _Noreturn
+# elif 2 < __GNUC__ + (8 <= __GNUC_MINOR__)
+#  define ATTRIBUTE_NORETURN __attribute__((noreturn))
 # else
-#  define _Noreturn
+#  define ATTRIBUTE_NORETURN /* empty */
+# endif
+#endif
+
+#if HAVE_HAS_C_ATTRIBUTE
+# if __has_c_attribute(reproducible)
+#  define ATTRIBUTE_REPRODUCIBLE [[reproducible]]
+# endif
+#endif
+#ifndef ATTRIBUTE_REPRODUCIBLE
+# if 3 <= __GNUC__
+#  define ATTRIBUTE_REPRODUCIBLE __attribute__((pure))
+# else
+#  define ATTRIBUTE_REPRODUCIBLE /* empty */
+# endif
+#endif
+
+#if HAVE_HAS_C_ATTRIBUTE
+# if __has_c_attribute(unsequenced)
+#  define ATTRIBUTE_UNSEQUENCED [[unsequenced]]
+# endif
+#endif
+#ifndef ATTRIBUTE_UNSEQUENCED
+# if 3 <= __GNUC__
+#  define ATTRIBUTE_UNSEQUENCED __attribute__((const))
+# else
+#  define ATTRIBUTE_UNSEQUENCED /* empty */
 # endif
 #endif
 
@@ -541,7 +628,7 @@ char *asctime(struct tm const *);
 char *asctime_r(struct tm const *restrict, char *restrict);
 char *ctime(time_t const *);
 char *ctime_r(time_t const *, char *);
-double difftime(time_t, time_t) ATTRIBUTE_CONST;
+double difftime(time_t, time_t) ATTRIBUTE_UNSEQUENCED;
 size_t strftime(char *restrict, size_t, char const *restrict,
 		struct tm const *restrict);
 # if HAVE_STRFTIME_L
@@ -554,9 +641,24 @@ struct tm *localtime(time_t const *);
 struct tm *localtime_r(time_t const *restrict, struct tm *restrict);
 time_t mktime(struct tm *);
 time_t time(time_t *);
+time_t timegm(struct tm *);
 void tzset(void);
 #endif
 
+#ifndef HAVE_DECL_TIMEGM
+# if (202311 <= __STDC_VERSION__ \
+      || defined __GLIBC__ || defined __tm_zone /* musl */ \
+      || defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ \
+      || (defined __APPLE__ && defined __MACH__))
+#  define HAVE_DECL_TIMEGM true
+# else
+#  define HAVE_DECL_TIMEGM false
+# endif
+#endif
+#if !HAVE_DECL_TIMEGM && !defined timegm
+time_t timegm(struct tm *);
+#endif
+
 #if !HAVE_DECL_ASCTIME_R && !defined asctime_r
 extern char *asctime_r(struct tm const *restrict, char *restrict);
 #endif
@@ -593,9 +695,6 @@ extern long altzone;
 # if TZ_TIME_T || !defined offtime
 struct tm *offtime(time_t const *, long);
 # endif
-# if TZ_TIME_T || !defined timegm
-time_t timegm(struct tm *);
-# endif
 # if TZ_TIME_T || !defined timelocal
 time_t timelocal(struct tm *);
 # endif
@@ -613,6 +712,7 @@ time_t posix2time(time_t);
 /* Infer TM_ZONE on systems where this information is known, but suppress
    guessing if NO_TM_ZONE is defined.  Similarly for TM_GMTOFF.  */
 #if (defined __GLIBC__ \
+     || defined __tm_zone /* musl */ \
      || defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ \
      || (defined __APPLE__ && defined __MACH__))
 # if !defined TM_GMTOFF && !defined NO_TM_GMTOFF
@@ -640,10 +740,10 @@ timezone_t tzalloc(char const *);
 void tzfree(timezone_t);
 # ifdef STD_INSPIRED
 #  if TZ_TIME_T || !defined posix2time_z
-time_t posix2time_z(timezone_t, time_t) ATTRIBUTE_PURE;
+time_t posix2time_z(timezone_t, time_t) ATTRIBUTE_REPRODUCIBLE;
 #  endif
 #  if TZ_TIME_T || !defined time2posix_z
-time_t time2posix_z(timezone_t, time_t) ATTRIBUTE_PURE;
+time_t time2posix_z(timezone_t, time_t) ATTRIBUTE_REPRODUCIBLE;
 #  endif
 # endif
 #endif

diff --git a/southamerica b/southamerica
@@ -1418,9 +1418,14 @@ Zone Antarctica/Palmer	0	-	-00	1965
 # Milne gives 4:56:16.4 for Bogotá time in 1899.  He writes,
 # "A variation of fifteen minutes in the public clocks of Bogota is not rare."
 
+# From Alois Treindl (2022-11-10):
+# End of time change in Colombia 1993 ... should be 6 February 24h ...
+# DECRETO 267 DE 1993
+# https://www.suin-juriscol.gov.co/viewDocument.asp?ruta=Decretos/1061335
+
 # Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
-Rule	CO	1992	only	-	May	 3	0:00	1:00	-
+Rule	CO	1992	only	-	May	 3	 0:00	1:00	-
-Rule	CO	1993	only	-	Apr	 4	0:00	0	-
+Rule	CO	1993	only	-	Feb	 6	24:00	0	-
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 		#STDOFF	-4:56:16.4
 Zone	America/Bogota	-4:56:16 -	LMT	1884 Mar 13

diff --git a/strftime.c b/strftime.c
@@ -117,7 +117,7 @@ static char *	_yconv(int, int, bool, bool, char *, char const *);
 #if HAVE_STRFTIME_L
 size_t
 strftime_l(char *s, size_t maxsize, char const *format, struct tm const *t,
-	   locale_t locale)
+	   ATTRIBUTE_MAYBE_UNUSED locale_t locale)
 {
   /* Just call strftime, as only the C locale is supported.  */
   return strftime(s, maxsize, format, t);
@@ -319,12 +319,21 @@ _fmt(const char *format, const struct tm *t, char *pt,
 								time_t) + 1];
 					time_t		mkt;
 
-					tm = *t;
+					tm.tm_sec = t->tm_sec;
+					tm.tm_min = t->tm_min;
+					tm.tm_hour = t->tm_hour;
+					tm.tm_mday = t->tm_mday;
+					tm.tm_mon = t->tm_mon;
+					tm.tm_year = t->tm_year;
+					tm.tm_isdst = t->tm_isdst;
+#if defined TM_GMTOFF && ! UNINIT_TRAP
+					tm.TM_GMTOFF = t->TM_GMTOFF;
+#endif
 					mkt = mktime(&tm);
-					/* There is no portable, definitive
+					/* If mktime fails, %s expands to the
-					   test for whether whether mktime
+					   value of (time_t) -1 as a failure
-					   succeeded, so treat (time_t) -1 as
+					   marker; this is better in practice
-					   the success that it might be.  */
+					   than strftime failing.  */
 					if (TYPE_SIGNED(time_t)) {
 					  intmax_t n = mkt;
 					  sprintf(buf, "%"PRIdMAX, n);

diff --git a/theory.html b/theory.html
@@ -60,7 +60,6 @@ <h2 id="scope">Scope of the <code><abbr>tz</abbr></code> database</h2>
 American mountain time zone can choose from the timezones
 <code>America/Denver</code> which observes US-style daylight saving
 time (<abbr>DST</abbr>),
-<code>America/Mazatlan</code> which observes Mexican-style <abbr>DST</abbr>,
 and <code>America/Phoenix</code> which does not observe <abbr>DST</abbr>.
 Applications that also deal with past timestamps in the mountain time
 zone can choose from over a dozen timezones, such as

diff --git a/time2posix.3 b/time2posix.3
@@ -1,9 +1,11 @@
-.TH TIME2POSIX 3
+.\" This file is in the public domain, so clarified as of
+.\" 1996-06-05 by Arthur David Olson.
+.TH time2posix 3
 .SH NAME
 time2posix, posix2time \- convert seconds since the Epoch
 .SH SYNOPSIS
 .nf
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
 .el .ds - \-
 .B #include <time.h>
 .PP
@@ -58,7 +60,7 @@ expression for directly computing a time_t value from a given date/time,
 and the same relationship is assumed by some
 (usually older)
 applications.
-Any programs creating/dissecting time_t's
+Any programs creating/dissecting time_t values
 using such a relationship will typically not handle intervals
 over leap seconds correctly.
 .PP
@@ -93,7 +95,7 @@ Both of these are good indicators of the inferiority of the
 POSIX representation.
 .PP
 The following table summarizes the relationship between a time
-T and it's conversion to,
+T and its conversion to,
 and back from,
 the POSIX representation over the leap second inserted at the end of June,
 1993.
@@ -117,8 +119,8 @@ DATE	TIME	T	X=time2posix(T)	posix2time(X)
 .fi
 .PP
 If leap-second support is not enabled,
-local time_t's and
+local time_t and
-POSIX time_t's are equivalent,
+POSIX time_t values are equivalent,
 and both
 .B time2posix
 and
@@ -129,5 +131,3 @@ difftime(3),
 localtime(3),
 mktime(3),
 time(2)
-.\" This file is in the public domain, so clarified as of
-.\" 1996-06-05 by Arthur David Olson.
diff --git a/tzfile.5 b/tzfile.5
@@ -1,3 +1,5 @@
+.\" This file is in the public domain, so clarified as of
+.\" 1996-06-05 by Arthur David Olson.
 .TH TZFILE 5
 .SH NAME
 tzfile \- timezone information
@@ -9,7 +11,7 @@ tzfile \- timezone information
 .de q
 \\$3\*(lq\\$1\*(rq\\$2
 ..
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
 .el .ds - \-
 The timezone information files used by
 .BR tzset (3)
@@ -492,5 +494,3 @@ Internet RFC 8536
 .UR https://\:doi.org/\:10.17487/\:RFC8536
 doi:10.17487/RFC8536
 .UE .
-.\" This file is in the public domain, so clarified as of
-.\" 1996-06-05 by Arthur David Olson.
diff --git a/tzselect.8 b/tzselect.8
@@ -1,8 +1,10 @@
+.\" This file is in the public domain, so clarified as of
+.\" 2009-05-17 by Arthur David Olson.
 .TH TZSELECT 8
 .SH NAME
 tzselect \- select a timezone
 .SH SYNOPSIS
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
 .el .ds - \-
 .ds d " degrees
 .ds m " minutes
@@ -121,5 +123,3 @@ newctime(3), tzfile(5), zdump(8), zic(8)
 Applications should not assume that
 .BR tzselect 's
 output matches the user's political preferences.
-.\" This file is in the public domain, so clarified as of
-.\" 2009-05-17 by Arthur David Olson.
diff --git a/zdump.8 b/zdump.8
@@ -1,4 +1,6 @@
-.TH ZDUMP 8
+.\" This file is in the public domain, so clarified as of
+.\" 2009-05-17 by Arthur David Olson.
+.TH zdump 8
 .SH NAME
 zdump \- timezone dumper
 .SH SYNOPSIS
@@ -16,7 +18,7 @@ zdump \- timezone dumper
 .de q
 \\$3\*(lq\\$1\*(rq\\$2
 ..
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
 .el .ds - \-
 The
 .B zdump
@@ -149,7 +151,7 @@ Here is an example of the output, with the leading empty line omitted.
 tabbed columns line up.)
 .nf
 .sp
-.if \n(.g .ft CW
+.if \n(.g .ft CR
 .if t .in +.5i
 .if n .in +2
 .nr w \w'1896-01-13  'u+\n(.i
@@ -182,7 +184,7 @@ UT, a standard time abbreviated HST.
 Here are excerpts from another example:
 .nf
 .sp
-.if \n(.g .ft CW
+.if \n(.g .ft CR
 .if t .in +.5i
 .if n .in +2
 TZ="Europe/Astrakhan"
@@ -227,5 +229,3 @@ introduction of UTC is problematic.
 .SH SEE ALSO
 .BR tzfile (5),
 .BR zic (8)
-.\" This file is in the public domain, so clarified as of
-.\" 2009-05-17 by Arthur David Olson.
diff --git a/zdump.c b/zdump.c
@@ -84,20 +84,20 @@ static time_t const absolute_max_time =
    ? (((time_t) 1 << atime_shift) - 1 + ((time_t) 1 << atime_shift))
    : -1);
 static int	longest;
-static char *	progname;
+static char const *progname;
 static bool	warned;
 static bool	errout;
 
 static char const *abbr(struct tm const *);
-static intmax_t	delta(struct tm *, struct tm *) ATTRIBUTE_PURE;
+static intmax_t	delta(struct tm *, struct tm *) ATTRIBUTE_REPRODUCIBLE;
 static void dumptime(struct tm const *);
-static time_t hunt(timezone_t, char *, time_t, time_t, bool);
+static time_t hunt(timezone_t, time_t, time_t, bool);
 static void show(timezone_t, char *, time_t, bool);
 static void showextrema(timezone_t, char *, time_t, struct tm *, time_t);
 static void showtrans(char const *, struct tm const *, time_t, char const *,
 		      char const *);
 static const char *tformat(void);
-static time_t yeartot(intmax_t) ATTRIBUTE_PURE;
+static time_t yeartot(intmax_t) ATTRIBUTE_REPRODUCIBLE;
 
 /* Is C an ASCII digit?  */
 static bool
@@ -125,16 +125,28 @@ is_alpha(char a)
 	}
 }
 
-/* Return A + B, exiting if the result would overflow.  */
+static ATTRIBUTE_NORETURN void
-static size_t
+size_overflow(void)
+{
+  fprintf(stderr, _("%s: size overflow\n"), progname);
+  exit(EXIT_FAILURE);
+}
+
+/* Return A + B, exiting if the result would overflow either ptrdiff_t
+   or size_t.  */
+static ATTRIBUTE_REPRODUCIBLE ptrdiff_t
 sumsize(size_t a, size_t b)
 {
-  size_t sum = a + b;
+#ifdef ckd_add
-  if (sum < a) {
+  ptrdiff_t sum;
-    fprintf(stderr, _("%s: size overflow\n"), progname);
+  if (!ckd_add(&sum, a, b) && sum <= SIZE_MAX)
-    exit(EXIT_FAILURE);
+    return sum;
-  }
+#else
-  return sum;
+  ptrdiff_t sum_max = min(PTRDIFF_MAX, SIZE_MAX);
+  if (a <= sum_max && b <= sum_max - a)
+    return a + b;
+#endif
+  size_overflow();
 }
 
 /* Return a pointer to a newly allocated buffer of size SIZE, exiting
@@ -234,22 +246,30 @@ tzalloc(char const *val)
     exit(EXIT_FAILURE);
   }
   tzset();
-  return NULL;
+  return &optarg;  /* Any valid non-null char ** will do.  */
 # else
   enum { TZeqlen = 3 };
   static char const TZeq[TZeqlen] = "TZ=";
   static char **fakeenv;
-  static size_t fakeenv0size;
+  static ptrdiff_t fakeenv0size;
   void *freeable = NULL;
   char **env = fakeenv, **initial_environ;
   size_t valsize = strlen(val) + 1;
   if (fakeenv0size < valsize) {
     char **e = environ, **to;
-    ptrdiff_t initial_nenvptrs;  /* Counting the trailing NULL pointer.  */
+    ptrdiff_t initial_nenvptrs = 1;  /* Counting the trailing NULL pointer.  */
-
+
-    while (*e++)
+    while (*e++) {
-      continue;
+#  ifdef ckd_add
-    initial_nenvptrs = e - environ;
+      if (ckd_add(&initial_nenvptrs, initial_envptrs, 1)
+	  || SIZE_MAX < initial_envptrs)
+	size_overflow();
+#  else
+      if (initial_nenvptrs == min(PTRDIFF_MAX, SIZE_MAX) / sizeof *environ)
+	size_overflow();
+      initial_nenvptrs++;
+#  endif
+    }
     fakeenv0size = sumsize(valsize, valsize);
     fakeenv0size = max(fakeenv0size, 64);
     freeable = env;
@@ -385,7 +405,7 @@ abbrok(const char *const abbrp, const char *const zone)
    return the abbreviation.  Get the abbreviation from TMP.
    Exit on memory allocation failure.  */
 static char const *
-saveabbr(char **buf, size_t *bufalloc, struct tm const *tmp)
+saveabbr(char **buf, ptrdiff_t *bufalloc, struct tm const *tmp)
 {
   char const *ab = abbr(tmp);
   if (HAVE_LOCALTIME_RZ)
@@ -442,7 +462,7 @@ main(int argc, char *argv[])
 {
 	/* These are static so that they're initially zero.  */
 	static char *		abbrev;
-	static size_t		abbrevsize;
+	static ptrdiff_t	abbrevsize;
 
 	register int		i;
 	register bool		vflag;
@@ -463,7 +483,7 @@ main(int argc, char *argv[])
 # endif /* defined TEXTDOMAINDIR */
 	textdomain(TZ_DOMAIN);
 #endif /* HAVE_GETTEXT */
-	progname = argv[0];
+	progname = argv[0] ? argv[0] : "zdump";
 	for (i = 1; i < argc; ++i)
 		if (strcmp(argv[i], "--version") == 0) {
 			printf("zdump %s%s\n", PKGVERSION, TZVERSION);
@@ -483,7 +503,7 @@ main(int argc, char *argv[])
 	  case -1:
 	    if (! (optind == argc - 1 && strcmp(argv[optind], "=") == 0))
 	      goto arg_processing_done;
-	    /* Fall through.  */
+	    ATTRIBUTE_FALLTHROUGH;
 	  default:
 	    usage(stderr, EXIT_FAILURE);
 	  }
@@ -607,7 +627,7 @@ main(int argc, char *argv[])
 		      || (ab && (delta(&newtm, &tm) != newt - t
 				 || newtm.tm_isdst != tm.tm_isdst
 				 || strcmp(abbr(&newtm), ab) != 0))) {
-		    newt = hunt(tz, argv[i], t, newt, false);
+		    newt = hunt(tz, t, newt, false);
 		    newtmp = localtime_rz(tz, &newt, &newtm);
 		    newtm_ok = newtmp != NULL;
 		    if (iflag)
@@ -687,18 +707,18 @@ yeartot(intmax_t y)
 	return t;
 }
 
-/* Search for a discontinuity in timezone TZ with name NAME, in the
+/* Search for a discontinuity in timezone TZ, in the
    timestamps ranging from LOT through HIT.  LOT and HIT disagree
    about some aspect of timezone.  If ONLY_OK, search only for
    definedness changes, i.e., localtime succeeds on one side of the
    transition but fails on the other side.  Return the timestamp just
    before the transition from LOT's settings.  */
 
 static time_t
-hunt(timezone_t tz, char *name, time_t lot, time_t hit, bool only_ok)
+hunt(timezone_t tz, time_t lot, time_t hit, bool only_ok)
 {
 	static char *		loab;
-	static size_t		loabsize;
+	static ptrdiff_t	loabsize;
 	struct tm		lotm;
 	struct tm		tm;
 
@@ -787,7 +807,8 @@ adjusted_yday(struct tm const *a, struct tm const *b)
    my_gmtime_r and use its result instead of B.  Otherwise, B is the
    possibly nonnull result of an earlier call to my_gmtime_r.  */
 static long
-gmtoff(struct tm const *a, time_t *t, struct tm const *b)
+gmtoff(struct tm const *a, ATTRIBUTE_MAYBE_UNUSED time_t *t,
+       ATTRIBUTE_MAYBE_UNUSED struct tm const *b)
 {
 #ifdef TM_GMTOFF
   return a->TM_GMTOFF;
@@ -858,7 +879,7 @@ static void
 showextrema(timezone_t tz, char *zone, time_t lo, struct tm *lotmp, time_t hi)
 {
   struct tm localtm[2], gmtm[2];
-  time_t t, boundary = hunt(tz, zone, lo, hi, true);
+  time_t t, boundary = hunt(tz, lo, hi, true);
   bool old = false;
   hi = (SECSPERDAY < hi - boundary
 	? boundary + SECSPERDAY
@@ -937,7 +958,7 @@ my_snprintf(char *s, size_t size, char const *format, ...)
    fit, return the length that the string would have been if it had
    fit; do not overrun the output buffer.  */
 static int
-format_local_time(char *buf, size_t size, struct tm const *tm)
+format_local_time(char *buf, ptrdiff_t size, struct tm const *tm)
 {
   int ss = tm->tm_sec, mm = tm->tm_min, hh = tm->tm_hour;
   return (ss
@@ -960,7 +981,7 @@ format_local_time(char *buf, size_t size, struct tm const *tm)
    the length that the string would have been if it had fit; do not
    overrun the output buffer.  */
 static int
-format_utc_offset(char *buf, size_t size, struct tm const *tm, time_t t)
+format_utc_offset(char *buf, ptrdiff_t size, struct tm const *tm, time_t t)
 {
   long off = gmtoff(tm, &t, NULL);
   char sign = ((off < 0
@@ -989,11 +1010,11 @@ format_utc_offset(char *buf, size_t size, struct tm const *tm, time_t t)
    If the representation's length is less than SIZE, return the
    length; the representation is not null terminated.  Otherwise
    return SIZE, to indicate that BUF is too small.  */
-static size_t
+static ptrdiff_t
-format_quoted_string(char *buf, size_t size, char const *p)
+format_quoted_string(char *buf, ptrdiff_t size, char const *p)
 {
   char *b = buf;
-  size_t s = size;
+  ptrdiff_t s = size;
   if (!s)
     return size;
   *b++ = '"', s--;
@@ -1031,11 +1052,11 @@ format_quoted_string(char *buf, size_t size, char const *p)
       and omit any trailing tabs.  */
 
 static bool
-istrftime(char *buf, size_t size, char const *time_fmt,
+istrftime(char *buf, ptrdiff_t size, char const *time_fmt,
 	  struct tm const *tm, time_t t, char const *ab, char const *zone_name)
 {
   char *b = buf;
-  size_t s = size;
+  ptrdiff_t s = size;
   char const *f = time_fmt, *p;
 
   for (p = f; ; p++)
@@ -1044,9 +1065,9 @@ istrftime(char *buf, size_t size, char const *time_fmt,
     else if (!*p
 	     || (*p == '%'
 		 && (p[1] == 'f' || p[1] == 'L' || p[1] == 'Q'))) {
-      size_t formatted_len;
+      ptrdiff_t formatted_len;
-      size_t f_prefix_len = p - f;
+      ptrdiff_t f_prefix_len = p - f;
-      size_t f_prefix_copy_size = p - f + 2;
+      ptrdiff_t f_prefix_copy_size = sumsize(f_prefix_len, 2);
       char fbuf[100];
       bool oversized = sizeof fbuf <= f_prefix_copy_size;
       char *f_prefix_copy = oversized ? xmalloc(f_prefix_copy_size) : fbuf;
@@ -1078,7 +1099,7 @@ istrftime(char *buf, size_t size, char const *time_fmt,
 	  b += offlen, s -= offlen;
 	  if (show_abbr) {
 	    char const *abp;
-	    size_t len;
+	    ptrdiff_t len;
 	    if (s <= 1)
 	      return false;
 	    *b++ = '\t', s--;
@@ -1117,7 +1138,7 @@ showtrans(char const *time_fmt, struct tm const *tm, time_t t, char const *ab,
     putchar('\n');
   } else {
     char stackbuf[1000];
-    size_t size = sizeof stackbuf;
+    ptrdiff_t size = sizeof stackbuf;
     char *buf = stackbuf;
     char *bufalloc = NULL;
     while (! istrftime(buf, size, time_fmt, tm, t, ab, zone_name)) {

diff --git a/zic.8 b/zic.8
@@ -1,4 +1,6 @@
-.TH ZIC 8
+.\" This file is in the public domain, so clarified as of
+.\" 2009-05-17 by Arthur David Olson.
+.TH zic 8
 .SH NAME
 zic \- timezone compiler
 .SH SYNOPSIS
@@ -22,7 +24,7 @@ zic \- timezone compiler
 .el .ds > \(ra
 .ie \n(.g \{\
 .  ds : \:
-.  ds - \f(CW-\fP
+.  ds - \f(CR-\fP
 .\}
 .el \{\
 .  ds :
@@ -347,7 +349,9 @@ nor
 .q + .
 To allow for future extensions,
 an unquoted name should not contain characters from the set
-.q !$%&'()*,/:;<=>?@[\e]^`{|}~ .
+.ie \n(.g .q \f(CR!$%&\(aq()*,/:;<=>?@[\e]\(ha\(ga{|}\(ti\fP .
+.el .ie t .q \f(CW!$%&'()*,/:;<=>?@[\e]^\(ga{|}~\fP .
+.el .q !$%&'()*,/:;<=>?@[\e]^`{|}~ .
 .TP
 .B FROM
 Gives the first year in which the rule applies.
@@ -894,5 +898,3 @@ specifying transition instants using universal time.
 .SH SEE ALSO
 .BR tzfile (5),
 .BR zdump (8)
-.\" This file is in the public domain, so clarified as of
-.\" 2009-05-17 by Arthur David Olson.
diff --git a/zic.c b/zic.c
diff --git a/zone.tab b/zone.tab
@@ -114,8 +114,7 @@ CA	+4606-06447	America/Moncton	Atlantic - New Brunswick
 CA	+5320-06025	America/Goose_Bay	Atlantic - Labrador (most areas)
 CA	+5125-05707	America/Blanc-Sablon	AST - QC (Lower North Shore)
 CA	+4339-07923	America/Toronto	Eastern - ON, QC (most areas)
-CA	+6344-06828	America/Iqaluit	Eastern - NU (most east areas)
+CA	+6344-06828	America/Iqaluit	Eastern - NU (most areas)
-CA	+6608-06544	America/Pangnirtung	Eastern - NU (Pangnirtung)
 CA	+484531-0913718	America/Atikokan	EST - ON (Atikokan); NU (Coral H)
 CA	+4953-09709	America/Winnipeg	Central - ON (west); Manitoba
 CA	+744144-0944945	America/Resolute	Central - NU (Resolute)
@@ -277,17 +276,18 @@ MT	+3554+01431	Europe/Malta
 MU	-2010+05730	Indian/Mauritius
 MV	+0410+07330	Indian/Maldives
 MW	-1547+03500	Africa/Blantyre
-MX	+1924-09909	America/Mexico_City	Central Time
+MX	+1924-09909	America/Mexico_City	Central Mexico
-MX	+2105-08646	America/Cancun	Eastern Standard Time - Quintana Roo
+MX	+2105-08646	America/Cancun	Quintana Roo
-MX	+2058-08937	America/Merida	Central Time - Campeche, Yucatan
+MX	+2058-08937	America/Merida	Campeche, Yucatan
-MX	+2540-10019	America/Monterrey	Central Time - Durango; Coahuila, Nuevo Leon, Tamaulipas (most areas)
+MX	+2540-10019	America/Monterrey	Durango; Coahuila, Nuevo Leon, Tamaulipas (most areas)
-MX	+2550-09730	America/Matamoros	Central Time US - Coahuila, Nuevo Leon, Tamaulipas (US border)
+MX	+2550-09730	America/Matamoros	Coahuila, Nuevo Leon, Tamaulipas (US border)
-MX	+2313-10625	America/Mazatlan	Mountain Time - Baja California Sur, Nayarit, Sinaloa
+MX	+2838-10605	America/Chihuahua	Chihuahua (most areas)
-MX	+2838-10605	America/Chihuahua	Mountain Time - Chihuahua (most areas)
+MX	+3144-10629	America/Ciudad_Juarez	Chihuahua (US border - west)
-MX	+2934-10425	America/Ojinaga	Mountain Time US - Chihuahua (US border)
+MX	+2934-10425	America/Ojinaga	Chihuahua (US border - east)
-MX	+2904-11058	America/Hermosillo	Mountain Standard Time - Sonora
+MX	+2313-10625	America/Mazatlan	Baja California Sur, Nayarit (most areas), Sinaloa
-MX	+3232-11701	America/Tijuana	Pacific Time US - Baja California
+MX	+2048-10515	America/Bahia_Banderas	Bahia de Banderas
-MX	+2048-10515	America/Bahia_Banderas	Central Time - Bahia de Banderas
+MX	+2904-11058	America/Hermosillo	Sonora
+MX	+3232-11701	America/Tijuana	Baja California
 MY	+0310+10142	Asia/Kuala_Lumpur	Malaysia (peninsula)
 MY	+0133+11020	Asia/Kuching	Sabah, Sarawak
 MZ	-2558+03235	Africa/Maputo

diff --git a/zone1970.tab b/zone1970.tab
@@ -102,8 +102,7 @@ CA	+4612-05957	America/Glace_Bay	Atlantic - NS (Cape Breton)
 CA	+4606-06447	America/Moncton	Atlantic - New Brunswick
 CA	+5320-06025	America/Goose_Bay	Atlantic - Labrador (most areas)
 CA,BS	+4339-07923	America/Toronto	Eastern - ON, QC (most areas), Bahamas
-CA	+6344-06828	America/Iqaluit	Eastern - NU (most east areas)
+CA	+6344-06828	America/Iqaluit	Eastern - NU (most areas)
-CA	+6608-06544	America/Pangnirtung	Eastern - NU (Pangnirtung)
 CA	+4953-09709	America/Winnipeg	Central - ON (west); Manitoba
 CA	+744144-0944945	America/Resolute	Central - NU (Resolute)
 CA	+624900-0920459	America/Rankin_Inlet	Central - NU (central)
@@ -214,17 +213,18 @@ MQ	+1436-06105	America/Martinique
 MT	+3554+01431	Europe/Malta
 MU	-2010+05730	Indian/Mauritius
 MV,TF	+0410+07330	Indian/Maldives	Maldives, Kerguelen, St Paul I, Amsterdam I
-MX	+1924-09909	America/Mexico_City	Central Time
+MX	+1924-09909	America/Mexico_City	Central Mexico
-MX	+2105-08646	America/Cancun	Eastern Standard Time - Quintana Roo
+MX	+2105-08646	America/Cancun	Quintana Roo
-MX	+2058-08937	America/Merida	Central Time - Campeche, Yucatán
+MX	+2058-08937	America/Merida	Campeche, Yucatán
-MX	+2540-10019	America/Monterrey	Central Time - Durango; Coahuila, Nuevo León, Tamaulipas (most areas)
+MX	+2540-10019	America/Monterrey	Durango; Coahuila, Nuevo León, Tamaulipas (most areas)
-MX	+2550-09730	America/Matamoros	Central Time US - Coahuila, Nuevo León, Tamaulipas (US border)
+MX	+2550-09730	America/Matamoros	Coahuila, Nuevo León, Tamaulipas (US border)
-MX	+2313-10625	America/Mazatlan	Mountain Time - Baja California Sur, Nayarit, Sinaloa
+MX	+2838-10605	America/Chihuahua	Chihuahua (most areas)
-MX	+2838-10605	America/Chihuahua	Mountain Time - Chihuahua (most areas)
+MX	+3144-10629	America/Ciudad_Juarez	Chihuahua (US border - west)
-MX	+2934-10425	America/Ojinaga	Mountain Time US - Chihuahua (US border)
+MX	+2934-10425	America/Ojinaga	Chihuahua (US border - east)
-MX	+2904-11058	America/Hermosillo	Mountain Standard Time - Sonora
+MX	+2313-10625	America/Mazatlan	Baja California Sur, Nayarit (most areas), Sinaloa
-MX	+3232-11701	America/Tijuana	Pacific Time US - Baja California
+MX	+2048-10515	America/Bahia_Banderas	Bahía de Banderas
-MX	+2048-10515	America/Bahia_Banderas	Central Time - Bahía de Banderas
+MX	+2904-11058	America/Hermosillo	Sonora
+MX	+3232-11701	America/Tijuana	Baja California
 MY,BN	+0133+11020	Asia/Kuching	Sabah, Sarawak, Brunei
 MZ,BI,BW,CD,MW,RW,ZM,ZW	-2558+03235	Africa/Maputo	Central Africa Time
 NA	-2234+01706	Africa/Windhoek